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Atmospheric science
George Mason University
Events

Upcoming Events

Jul11

MS Project Presentation - Environmental Science and Policy

Jul 11, 2025, 1:00 - 2:30 PM

Register in advance for this meeting: Registration Link
After registering, you will receive a confirmation email containing information about joining the meeting.

Jul14

FOCUS Camp and Academy

Jul 14, 2025, 9:00 AM - Jul 18, 2025, 5:00 PM

Jul14

Dissertation Defense - Tianshu Yang - Department of Geography and Geoinformation Science

Jul 14, 2025, 10:30 AM - 12:00 PM

Exploratory Hall, Room 2312 

Virtual Meeting link: email tyang4@gmu.edu

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21 Jul (CLIM) Scott Knapp, PhD Defense

Jul 21, 2025, 10:30 - 11:30 AM

Scott Knapp, Doctor of Philosophy in Climate Dynamics

Sea Surface Temperature Gradients of the Pacific in Warm Climates

Mon, 21 Jul, 10:30am, Exploratory Hall rm 3301

Advisor: Natalie Burls

 

The sea surface temperatures (SST) of the Pacific Ocean have extremely important roles in setting global weather and climate. The relative SSTs of the east and west tropical Pacific affect large-scale atmospheric circulation like the Walker cell, while the relative SSTs of the tropical and subtropical Pacific affect the Hadley circulation. Both the Hadley and Walker influence global temperature, hydroclimate, poleward energy transport and radiation balance. It is not yet understood exactly how SST in the Pacific will change with global warming. This uncertainty is intricately related to the large spread of global warming predicted by different climate models. We aim to increase our understanding of how Pacific SSTs will change in the short and long term in response to greenhouse gases by studying regional changes of dynamic and radiative processes. We explore the coupled ocean-atmosphere relationship between regional

radiative feedback and large-scale SST gradients using a simplified box model forced with an abrupt quadrupling of atmospheric CO2 concentrations. The sensitivity of zonal and meridional upper ocean temperature (TUO) gradients to regional feedback parameter (λ) configurations is tested by simulating 1296 combinations of regional λ. We identify thresholds of λ differences between regions which are strong enough to allow the regional radiative response to overcome the TUO gradient weakening tendencies of the oceanic and atmospheric energy transport in the box model. We next quantify how transient changes in the zonal Pacific SST gradient (the thermostat mechanism) and transient versus equilibrium changes in global mean λ (the “pattern effect”) are related between models and to each other, and to the global mean surface temperature change at equilibrium resulting from a doubling of CO2 in CMIP6.

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